In movies and on television, the serial killer's been done to death.

We're all familiar with the telltale signs: the dug-out pit in the basement; the keeps-to-himself profile; and the shifty five o'clock shadow.

Meet Dexter Morgan, a new breed of psychopath.

Michael C. Hall is the star of "Dexter," a fascinating new Sunday night Showtime series about a Miami lawman who moonlights as brutal serial killer, using the same barbarous tactics of those he is trying to catch. But this avenger is one who only choppity-chops the bad guys who have either outsmarted the legal system or are guilty but haven't been caught.

Far-fetched, perhaps, but the concept works, thanks to Hall's riveting, underplayed performance as a guy who's well-liked despite caring about people "as much as I care about lawn furniture." That emotional detachment makes him a heckuva blood-splatter expert (his official job title), but it also suits his brutal hobby.

As Dexter, Hall successfully sheds the image of uptight, repressed funeral-home owner David Fisher from the now-departed HBO series "Six Feet Under." (What is it with this guy and death?) But, at the same time, Hall actually incorporates some of the characteristics of Fisher into his portrayal of Dexter.

"I'm a very neat monster," Dexter says, fittingly describing himself in a monotone narration used effectively throughout the series.

After dispatching his victims -- with the help of drills, knives, duct tape and lots and lots of cellophane -- Dexter keeps a tiny sample of their blood on a glass slide, which is kept in a wooden case hidden behind the air conditioner of his apartment.

It's all very tidy.

We're not too sure yet how Dexter got the way he is but, luckily, his foster father, Harry (James Remar, the creepy onetime boyfriend of Samantha on "Sex and the City"), knew early on he was a natural-born killer. "Maybe we can do something to channel it -- use it for good," he tells his teenage son in one of many flashbacks.

So begins Dad's training of Dexter, which we come to know as the "Code of Harry." It includes: Don't go hunting after random individuals but rather those who have it comin', and make sure to "always cover your tracks."

The foster dad is one of many appealing supporting characters. Dexter might have to fake human interaction, as he says, but that doesn't stop him from having a girlfriend. Rita (ably played by Julie Benz) is "equally damaged" because of a brutal first marriage, but they are content in their sexless companionship. Slowly, though, with the help of her two adorable kids, we start seeing Dexter evolve.

It's clearly an uphill battle. As Dexter puts it: "The willful taking of life represents the ultimate disconnect from humanity."

There's beauty to be found in even the most gruesome scenes. In tomorrow night's premiere, Dexter oversees a crime scene as if it's an art exhibition, using red string to illustrate the trajectory of blood in an all-white living room. Dexter acts like a curator, breathlessly explaining to a colleague how the homicide went down.

At times it can be graphic, but there's nothing here you wouldn't see on a "sweeps" episode of CBS's "CSI," which makes sense. "Dexter" is the latest series on the Showtime lineup developed under the control of CBS President Les Moonves, who's company took Showtime under its wing last year. Moonves recently criticized Showtime as "a little too much of an off-Broadway play" and said he wanted the network to become more commercial.

At times, the series falls into the trap of being just another procedural crime drama. The second episode introduces a plotline dealing with a crime boss suspected of killing a cop and his wife. One of the detectives approaches the mobster at his daughter's confirmation and makes a scene -- something done decades ago on "Miami Vice."

But the dominating story line, which looks to last the entire season, is mesmerizing. Dexter is on the trail of a serial killer who has a very unique way of disposing of his victims (let's just say no blood is involved and refrigeration is needed). The twist is that this villain knows that Dexter is after him and leaves him little trinkets, like severed fingertips.

After finding one such souvenir in his own freezer, Dexter says: "I think this is a friendly message like, 'Hey, wanna play?' And, yes, I do. I really do."

Thanks to Hall's performance, so do we.